Question

ABC is an isosceles triangle with AB equal to AC equal to 12 cm and BC equal to 8 cm find the altitude on the BC and hence calculate its area​

Answer 1

Step-by-step explanation:

Given;

ABC is an isosceles tri.

AB= AC = 12cm.

BC = 8cm.

as,else know that altitude bisects the base ...

so., let the altitude be AO on BC

BO= 1/2 × 8

= 4cm.

and ,by Pythagoras theorem;

in ∆ AOB;

AB² = OB ²+ AO²

= 12²= 4²+ AO²

= AO²= 12²-4²

= AO²=(12+4)(12-4)

= AO²= 16× 8

= AO= √ 16× 8= 8√ 2cm..

so,the altitude AO= 8√ 2 cm.

and ,the area of the tri.=

1/2× base × height

= 1/2 × 8× 8√ 2

=4× 8√ 2= 32√ 2cm ².

hence,the area of the tri. = 32√2cm².(ans).

hey,mates here is Ur ans...hope it's helpful ...thnx....